This invention relates to reflective sheet material for use on exterior signs, buildings and vehicles, signs made with this material, and methods of making reflective sheet material.
Reflective sheet materials for use on exterior signs, buildings, vehicles and various supporting surfaces are known and have been used for a number of years. For example, it is well known to construct stop signs and other road signs using reflective material on the front surface of the sign so that the sign can be readily seen, particularly at night or in low light conditions. The use of reflective material on vehicles is also common in order that others can see a vehicle easily at night from the reflection of headlights off the material. The use of reflective material can reduce the need for or eliminate the need for the use of electrical lights in a sign so that it can be easily seen or so that it will attract attention. The use of reflective material can provide the sign, vehicle or building with an original and striking appearance and often at a reasonable cost.
One common form of sign used by many stores is the so-called “neon sign” which uses electricity to power neon tubes. However, such signs have several disadvantages including a relatively high cost. Also, the type and complexity of the images that can be produced by neon tubes is somewhat limited. Because electricity is required to power such neon signs, the expense of operating same, particularly for an extended period of time, can be significant.
U.S. Pat. No. 2,193,057 issued Mar. 12, 1940 to N. P. Carver teaches a sign construction which employs a rigid back support and a front stenciled member in which are formed cutouts or openings forming desired letters of the sign. Mounted behind the stenciled member is a panel made of transparent or translucent material such as glass or a suitable synthetic resin. The front surface of this panel comprises a pebbled surface in order to disseminate incoming light rays throughout the panel. In one embodiment, this panel has a prismatic rear face for refracting the light rays entering the pebbled surface and reflecting them out of the panel towards a motorist, for example. The rear face of this panel can be covered with a lustrous finish or coating which is said to enhance the reflecting of the light rays.
More recent U.S. Pat. No. 6,612,055 describes and illustrates another sign panel which can use ambient light. This panel employs a transparent, phosphorescent, plastic sheet having a rearward surface in which grooves are formed in order to outline desired indicia. Additional grooves are also provided in the rearward surface, these forming hatch patterns within the outlines of the selected indicia, which are also viewable from the forward surface. This sign panel relies on light that is transferred through the sheet in a direction perpendicular to its forward and rearward planar surfaces.
U.S. Pat. No. 3,651,590 issued Mar. 28, 1972 to F. O. Thomas describes a sign with indicia shaped apertures in an outer framework. The apertures expose a reflective core mounted in a recess within the framework. The textured surfaces provided in the reflective core are said to provide multi-directional reflectivity that contrasts with the outer framework. In particular, the core can be made with clear plastic front and back sheets and between these sheets is a textured, metalized inner surface that can be formed by a series of parallel grooves formed in the adjacent surfaces of the two sheets. A metallic layer can be provided on the grooved surfaces to achieve the reflective surface.
There is a need for an improved reflective sheet material that can be used in the construction of exterior signs and the provision of reflective surfaces on vehicles and buildings and that can be made at a reasonable cost. In particular there remains a need for an improved reflective sheet material that can efficiently use ambient light so as to provide an enhanced light reflecting capability in order to provide better signs and better reflecting surfaces.